Connections between microwave transmission lines have heretofore been constructed by employing a reed contact extending across a pair of parallel microwave probes representing an output line and an input line. In a contact position, the reed contact allows passage of microwave signals. In a reed contact disengaged position there is no connection between the probes and no microwave signal passes from the outlet probe to the inlet probe. In the prior art, a spring-loaded plastic post has been positioned above the reed contact and a solenoid plunger actuated to push the post against the post and move the reed contact into probe contact. In another prior art device, a pivotable iron bar is provided which is pivoted by a permanent magnet to a first position which presses a post against the reed contact to effect probe contacts and the bar pivoted to a second position by a solenoid so that the bar is out of operating contact with the reed contact thus disconnecting the switch. The above prior art devices generally have a relatively short cycle life of about one million cycles due to friction, impact stresses, pivot wear and metal fatigue. Further, these prior art devices have multiple moving parts and assemblies resulting in an expensive construction and relatively low durability.